如何在C＃中的畫布上製作一條線？

Question

你會如何讓一條線緩慢地穿過屏幕？

我想在C＃/ WPF項目的畫布上設置一條線。

我想使用C＃代碼而不是XML。

謝謝。

Answer 1

您將需要使用Storyboard和動畫Line.X2和Line.Y2屬性。看看這是否適合你。

MainWindow.xaml

<Window x:Class="WpfApplication1.MainWindow" 
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
     Title="MainWindow" Height="350" Width="525"> 
    <Canvas Name="myCanvas"> 
     <Button Canvas.Left="248" Canvas.Top="222" Content="Button" Height="23" Name="button1" Width="75" Click="button1_Click" /> 
    </Canvas> 
</Window> 

按鈕單擊事件

private void button1_Click(object sender, RoutedEventArgs e) 
{ 
    Line line = new Line(); 
    myCanvas.Children.Add(line); 
    line.Stroke = Brushes.Red; 
    line.StrokeThickness = 2; 
    line.X1 = 0; 
    line.Y1 = 0; 
    Storyboard sb = new Storyboard(); 
    DoubleAnimation da = new DoubleAnimation(line.Y2 , 100, new Duration(new TimeSpan(0, 0, 1))); 
    DoubleAnimation da1 = new DoubleAnimation(line.X2, 100, new Duration(new TimeSpan(0, 0, 1))); 
    Storyboard.SetTargetProperty(da, new PropertyPath("(Line.Y2)")); 
    Storyboard.SetTargetProperty(da1, new PropertyPath("(Line.X2)")); 
    sb.Children.Add(da); 
    sb.Children.Add(da1); 

    line.BeginStoryboard(sb); 


} 

Answer 2

我有一個正在運行的示例，它使用MVVM模式並在ListBox內創建Canvas作爲ItemsPanel的行。

我實際上是爲this question做的，但OP的那種消失了，從來沒有和我聯繫過。

這就是它看起來像在我的電腦：

它的主要部分是這樣的：

<ListBox ItemsSource="{Binding}" x:Name="lst" Height="500" Width="500"> 
      <ListBox.ItemsPanel> 
       <ItemsPanelTemplate> 
        <Canvas IsItemsHost="True"/> 
       </ItemsPanelTemplate> 
      </ListBox.ItemsPanel> 
      <ListBox.ItemContainerStyle> 
       <Style TargetType="ListBoxItem"> 
        <Setter Property="FocusVisualStyle"> 
         <Setter.Value> 
          <Style TargetType="Control"> 
           <Setter Property="Opacity" Value="0"/> 
          </Style> 
         </Setter.Value> 
        </Setter> 
        <Setter Property="Template"> 
         <Setter.Value> 
          <ControlTemplate TargetType="ListBoxItem"> 
           <Line X1="{Binding X1}" Y1="{Binding Y1}" 
             X2="{Binding X2}" Y2="{Binding Y2}" 
             StrokeThickness="{Binding Thickness}" 
             Opacity="{Binding Opacity}" 
             x:Name="Line"> 
            <Line.Stroke> 
             <LinearGradientBrush StartPoint="0,0" EndPoint="1,1"> 
              <GradientStop Color="{Binding Color1}" Offset="0"/> 
              <GradientStop Color="{Binding Color2}" Offset="1"/> 
             </LinearGradientBrush> 
            </Line.Stroke> 
           </Line> 
           <ControlTemplate.Triggers> 
            <Trigger Property="IsSelected" Value="true"> 
             <Setter Property="Effect" TargetName="Line"> 
              <Setter.Value> 
               <DropShadowEffect Color="CornflowerBlue" ShadowDepth="3" BlurRadius="10"/> 
              </Setter.Value> 
             </Setter> 
            </Trigger> 
           </ControlTemplate.Triggers> 
          </ControlTemplate> 
         </Setter.Value> 
        </Setter> 
       </Style> 
      </ListBox.ItemContainerStyle> 
     </ListBox> 

視圖模型：

public class LineViewModel : INotifyPropertyChanged 
    { 
     #region Timer-based Animation 

     private System.Threading.Timer Timer; 
     private static Random Rnd = new Random(); 

     private bool _animate; 
     public bool Animate 
     { 
      get { return _animate; } 
      set 
      { 
       _animate = value; 
       NotifyPropertyChanged("Animate"); 
       if (value) 
        StartTimer(); 
       else 
        StopTimer(); 
      } 
     } 

     private int _animationSpeed = 1; 
     public int AnimationSpeed 
     { 
      get { return _animationSpeed; } 
      set 
      { 
       _animationSpeed = value; 
       NotifyPropertyChanged("AnimationSpeed"); 
       if (Timer != null) 
        Timer.Change(0, 100/value); 
      } 
     } 

     private static readonly List<int> _animationSpeeds = new List<int>{1,2,3,4,5}; 
     public List<int> AnimationSpeeds 
     { 
      get { return _animationSpeeds; } 
     } 

     public void StartTimer() 
     { 
      StopTimer(); 
      Timer = new Timer(x => Timer_Tick(), null, 0, 100/AnimationSpeed); 
     } 

     public void StopTimer() 
     { 
      if (Timer != null) 
      { 
       Timer.Dispose(); 
       Timer = null; 
      } 
     } 

     private void Timer_Tick() 
     { 
      X1 = X1 + Rnd.Next(-2, 3); 
      Y1 = Y1 + Rnd.Next(-2, 3); 
      X2 = X2 + Rnd.Next(-2, 3); 
      Y2 = Y2 + Rnd.Next(-2, 3); 
     } 

     #endregion 

     #region Coordinates 

     private double _x1; 
     public double X1 
     { 
      get { return _x1; } 
      set 
      { 
       _x1 = value; 
       NotifyPropertyChanged("X1"); 
      } 
     } 

     private double _y1; 
     public double Y1 
     { 
      get { return _y1; } 
      set 
      { 
       _y1 = value; 
       NotifyPropertyChanged("Y1"); 
      } 
     } 

     private double _x2; 
     public double X2 
     { 
      get { return _x2; } 
      set 
      { 
       _x2 = value; 
       NotifyPropertyChanged("X2"); 
      } 
     } 

     private double _y2; 
     public double Y2 
     { 
      get { return _y2; } 
      set 
      { 
       _y2 = value; 
       NotifyPropertyChanged("Y2"); 
      } 
     } 

     #endregion 

     #region Other Properties 

     private string _name; 
     public string Name 
     { 
      get { return _name; } 
      set 
      { 
       _name = value; 
       NotifyPropertyChanged("Name"); 
      } 
     } 

     private double _thickness; 
     public double Thickness 
     { 
      get { return _thickness; } 
      set 
      { 
       _thickness = value; 
       NotifyPropertyChanged("Thickness"); 
      } 
     } 

     public Color Color1 { get; set; } 
     public Color Color2 { get; set; } 

     private double _opacity = 1; 
     public double Opacity 
     { 
      get { return _opacity; } 
      set 
      { 
       _opacity = value; 
       NotifyPropertyChanged("Opacity"); 
      } 
     } 

     #endregion 

     #region INotifyPropertyChanged 

     public event PropertyChangedEventHandler PropertyChanged; 

     private void NotifyPropertyChanged(string propertyName) 
     { 
      Application.Current.Dispatcher.BeginInvoke((Action)(() => 
       { 
        if (PropertyChanged != null) 
         PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
       })); 
     } 

     #endregion 
    } 

編輯：源代碼現在在GitHub